In some stores if you scan alcohol the machine will freeze until the attendant turns the key. In others, it flashes a light to alert the attendant. It allows y

In some stores if you scan alcohol the machine will freeze until the attendant turns the key. In others, it flashes a light to alert the attendant. It allows you to carry on scanning, but the attendant must turn the key before you pay. I just hope that isn't patented.